Using major nutrient concentrations to derive vertical movement of water masses in the coastal region of eastern Taiwan

Generation and Propagation of M2 Internal Tides Modulated by the Kuroshio Northeast of Taiwan

“…Our modeling results are generally consistent with field mooring measurements (Lien et al, ; Pai et al, ) and are qualitatively consistent with autonomous glider observations (Rainville et al, ) and eddy‐resolving numerical simulations (Varlamov et al, ), suggesting that the general pattern of M 2 internal tides is correctly characterized by the simulation with the quasi‐steady Kuroshio flows. Further numerical studies, including simultaneous modeling of the tides and mesoscale processes, are needed to address the variability of the internal tide energetics.…”

“…They speculated that the M 2 internal tides from the northern area cause strong vertical displacements near Hualien. The vertical displacements induced by the M 2 internal tides can be clearly discerned from a crosssectional snapshot of the horizontal velocity and isotherms near 24°N in our numerical results (Figures 15a and 15b), where a weak displacement is observed in the upper 300 m, while strong oscillations are detected beneath 400 m. The largest vertical displacement at Hualien reaches~70 m in our simulation (Figure 15b), which is comparable to the maximum displacement magnitude of~100 m observed by Pai et al (2017). Our modeling results suggest that the along-slope M 2 beam is generated at the two slopes of the I-Lan Ridge.…”

“…Based on mooring observations, Pai et al () recently reported the presence of strong internal tides off the Hualien coast, where the largest vertical isotherm displacement is around 300‐ to 1,000‐m depth (Figure b). They speculated that the M 2 internal tides from the northern area cause strong vertical displacements near Hualien.…”

“…Depth contours (200, 400, 600, 800, and 1,000 m) are shown as black thin lines. The red triangle in Figure a indicates the position of the field observation performed by Pai et al ().…”

“…Our modeling results suggest that the along-slope M 2 beam is generated at the two slopes of the I-Lan Ridge. The beam is capable of propagating over a distance of 100 km at a velocity of approximately 0.2 m/s in the upper 500 m, which is also consistent with the field observations (Pai et al, 2017). As suggested by Rainville and Pinkel (2004), the Kuroshio front can act as a wall due to the vertical component of geostrophic vorticity, and the low-mode internal tides can sneak beneath the Kuroshio during propagation.…”